Hiya - well I think the python installer is like 5 mb right? In the installation process it asks if you want sample scripts, tutorial etc. so a person could just check "no". Other then that - the really awesome thing about python, is jython, which essentially lets you run python inside any virtual java machine =)

Very doable actually

There's a wide variety of possibilities on how to distribute your Python app. I'd suggest you look at Gordon McMillan's pages on how to distribute python apps here: http://www.mcmillan-inc.com/install1.html .